As someone who has experience with the OPC, I do recommend you meeting with the pastor to get your questions answered. I do know that if you aren't a member of an evangelical church, they will not allow you to take the Lord's Supper. (If they do, they aren't following the denomination's rules.) I don't know your family situation. But I know of at least one OPC pastor who threatened to suspend a couple from the Lord's Supper if they didn't have their child baptized. The OPC tends to be quite a bit more strict on these things than the PCA.
I don't know whether or not you are a Sabbatarian, but they generally are strict on that as well. No eating out on Sunday, no unnecessary work, maybe no watching football and so on.
You might see if you can go to the far away Baptist church when able but attend the OPC congregation when that isn't possible. But some Baptist churches (as well as others) will expect you to be there every time the door opens, so that might not be possible. Also, explain your situation to the Baptist church that is far away. I've heard of churches that will actually provide financial support for transportation, etc. for those who live far away. A lot of Calvinistic Baptist churches are basically commuter churches, with much of the congregation driving 30 minutes to over an hour one way to get there. (If you're not Calvinistic, then you really must be in dire straits to consider attending an OPC congregation!)
Since you are considering attending an OPC congregation, I assume you consider yourself to be a "Reformed Baptist." You might also consider contacting ARBCA or F.I.R.E. to make sure there aren't others in your area who aren't interested in seeing a "true" church planted. It may be that there are others in your area that are traveling long distances. I assume you have checked the directories on 9 Marks, Founders, Farese and other RB sites? Founders has a "Founders Friends" category as well as a church category. But some of it may be out of date.